New PCR-based method for the Sp1 site polymorphism in the COL1A1 gene.

Polymorphism in the Sp1 binding site in the first intron of the COL1A1 gene has been related to increased risk of osteoporosis in several populations. To overcome the difficulties associated with the use of mismatch oligonucleotide primers in the original method for its detection, we developed a procedure involving PCR amplification of a 598-base pair sequence from the intron and its digestion with the restriction enzyme Van 91 I. The more frequent allele is recognized by the enzyme, whereas the reaction is abolished in the less frequent allele. Two convenience samples from the population in northern Finland, consisting altogether of 173 individuals, were studied. The overall frequencies were 0.864 for the G and 0.136 for the T allele, with a heterozygocity of 27.2%. The frequency of the T allele is towards the lower end of the range observed for other European populations.